Abstract: High-pressure discharge lamp having a ceramic discharge vessel, in which two electrodes and a light-emitting filling are contained, wherein capillaries are positioned at the ends of the discharge vessel, in which capillaries leadthroughs are sealed off, which leadthroughs are each connected to an electrode (15) consisting of tungsten. The electrode (15) is in the form of a pin and integrally comprises two parts (25, 26) having different diameters, wherein the first part (25) having a given diameter D1 forms the electrode tip, the second part (26) having a diameter D2 is positioned in the capillary, and the diameter D2 of the second part makes up at least 108% of the diameter D1 of the first part.

Abstract: High-pressure discharge lamp having a ceramic discharge vessel, in which two electrodes and a light-emitting filling are contained, wherein capillaries are positioned at the ends of the discharge vessel, in which capillaries leadthroughs are sealed off, which leadthroughs are each connected to an electrode (15) consisting of tungsten. The electrode (15) is in the form of a pin and integrally comprises two parts (25, 26) having different diameters, wherein the first part (25) having a given diameter D1 forms the electrode tip, the second part (26) having a diameter D2 is positioned in the capillary, and the diameter D2 of the second part makes up at least 108% of the diameter D1 of the first part.

Abstract: Flickering phenomena in gas discharge lamps are undesired in projection technology, in particular. According to the invention, the problem is solved by setting a lamp operation which does not form a focal spot. A specific control structure which includes a cascade structure and feedforward control is proposed for implementing this operation.

Abstract: The invention relates to a high-pressure discharge lamp, in particular a metal halide high-pressure discharge lamp, and a method for operating this lamp with the aid of a square-wave alternating current. According to the invention, the electrodes (2) of the lamp are dimensioned such that during operation of the lamp with its prescribed nominal power and with a substantially square-wave alternating current the product of the current density in the electrodes (2) and the cube root of the root mean square value of the alternating current has a constant value of between 5 A4/3mm−2 and 10 A4/3mm−2 during the stable operating state of the high-pressure discharge lamp after termination of the ignition phase.

Abstract: Flickering phenomena in gas discharge lamps are undesired in projection technology, in particular. According to the invention, the problem is solved by setting a lamp operation which does not form a focal spot. A specific control structure which includes a cascade structure and feedforward control is proposed for implementing this operation.

Abstract: A sintered electrode of high-melting metal (for example tungsten) is produced from spherical metal powder having a well defined particle size. The mean particle size is from 5 to 70 &mgr;m. The particle size distribution covers a range from at most 20% below to at most 20% above the mean particle size.

Abstract: The high-pressure sodium discharge lamp of low power described here is chcterized by a very high xenon cold filling pressure of at least 1 bar. The pressure ratio to the sodium operating pressures lies between 10 and 30. Luminous efficacies of approximately 100 lm/W and more can be obtained with a lamp power of 50 to 100 W.

Abstract: The method is suitable to make sodium high-pressure discharge lamps operag operating under saturated condition. After placing and melt-sealing a first electrode system into the discharge vessel, sodium is introduced in the form of NaN.sub.3 through the second end of the vessel. Upon heating of the second end, and due to heat conduction, the NaN.sub.3, collected at the first end, dissociates, resulting in a sudden pressure rise due to liberation of nitrogen within a vacuum. As soon as the nitrogen has dissipated, noble gas to cool the first end is introduced, and the second melt seal is then made. The noble gas may, at the same time, form an ignition gas, or a gas mixture for the discharge lamp. One or more half-finished lamps are preferably held in a holder structure which has vertical bores leaving a gap of between 0.2 to 3 mm between the wall surface of the bore and the vessel and, as such, are introduced into a vacuum furnace, where the pressure can be monitored.